


A Loud Evening

by sonicsora



Series: Oldies under the sea [2]
Category: Undertale (Video Game)
Genre: Aged-Up Character(s), Alphyne centric, F/F, Gen, Humor, Old People In Love, Romance, Undyne destroys jerry's life, mermaid au
Language: English
Status: Completed
Published: 2016-01-28
Updated: 2016-01-28
Packaged: 2018-05-15 12:28:44
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 3,270
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/5785339
Author URL: https://archiveofourown.org/users/sonicsora/pseuds/sonicsora
Summary: <blockquote class="userstuff">
              <p>Undyne begins her campaign to get rid of Jerry once and for all. Some rotten fish and shark sightings around his home should do the trick. Maybe a broken car window or two will seal the deal? </p><p>A sequel to 'A quiet afternoon'. Older Alphyne/Undyne. Mermaid AU.</p>
            </blockquote>





	A Loud Evening

**Author's Note:**

  * For [Amazinglybad](https://archiveofourown.org/users/Amazinglybad/gifts).



> After some thought, I decided 'A Quiet Evening' needed a sequel. Be it one that is more heavily focused on the couple in question without Frisk's filter over it.
> 
> Like it says on the tin, all the characters except Undyne are human. Along with that everyone is a little bit older. Alphys is 60. Toriel is her older sister (64), they are awkwardly trying to reconnect thanks to Frisk being such an enabler. 
> 
> and my apologies for anyone who likes Jerry. Undyne is a grade A asshole, haha.
> 
> Once again this is my girlfriend. Who deserves the very best.

Humans were weird. Cool, but weird. Undyne didn’t mind it too much honestly. If humanity made Alphys, Frisk and Papyrus, it couldn’t be all bad. The fact there were giant swords only made humans cooler as far as the mermaid was concerned. 

She occasionally reconsidered when she remembered _Jerry_. 

He threw cans, garbage and broken glass into the ocean. Undyne helpfully buried it in his yard for him to find. If it ended up in the ocean again, she would wrap it up and send it as a package to his mailbox. (After a certain point Alphys would just roll her eyes and send the packages herself to soothe her agitated fish of a wife.) He left passive aggressive notes in people's mailboxes. He smoked by their front gate, he loitered around the neighborhood loudly playing music and going through people's mail. He was generally obnoxious. It made Undyne's mission more clear the more she thought about it. 

_Get rid of Jerry._

The mermaid hunched low against the sand, tail slowly swishing behind her as she listened to the sound of footsteps overhead. With a smirk, Undyne yanked herself forward digging up the sand with her hands before reaching back to grab the sack of fish. With a low click of her teeth she dumped the bag’s contents out into the hole.

Undyne pat the sand down firmly to ensure the fish didn’t go anywhere.

She tied the bag back to her waist, moving down the path she had dug up for herself. It didn’t take long to find her way back to the water. The rush of water against her scales was a relief. Digging this tunnel had been a pain in the ass, but hopefully a worthwhile one.

Now all she had to do was wait. She emerged from the water to smirk at the house sloped onto the beach. The ringing of a bell made the mermaid perk up, gaze drifting towards her own home off in the distance.

Alphys wanted her back. 

She dove back under, swimming in the familiar waters towards her home.

\-----

With Alphys off to some nerd convention, it gave Undyne more than enough time to make sure her pet project was coming along. She hadn't really checked on it since she buried those fish two weeks ago.

She checked the house over one last time before diving back into her pool, swimming through the system built under the house to the gated exit. The mermaid punched in the code out of memory. Glad the she had gotten the hang of the keypad and the concept of human numbers years back. 

When the gate lifted Undyne quickly swam out, closing the gate tightly behind her before making off in the direction of Jerry's home. Some disgust settled low in her belly when she saw the usual remnants of the human's behavior in the sand below. Stray bottles, some plastic- a plastic bag floating along. 

Undyne grabbed the bag, quickly rounding up what trash she could find. She only paused to quickly kill a few fish, stuffing them into the bag as well. It was a waste of a perfectly good fish, but sacrifices had to be made. Undyne tied it off tightly as she could in the water.

She carried it with her as she continued further towards the shoreline that cut so close to the house. With some patting along the sand bank she found her tunnel, it only took a some minor digging to open it up again. 

Undyne pushed herself forward into the tunnel, dragging the bag along behind her. 

It didn't take long before the stench hit her. She was only partially through the tunnel when the rotten smell assaulted her nose. Undyne groaned, covering her face with a hand trying to ignore the stench. It only got worse the closer she dragged herself. 

She ignored the queasiness to push onwards, coming to a stop within sight of the pile of fish. Clearly predators had picked at the top layer, but there was more than enough to keep the smell going for another few weeks. She stuffed the bag of garbage against the established pile before pushing off back down the tunnel. 

\----

This wasn't her favorite way to spend a saturday, but she was going to find a rock. The biggest rock possible. It took some searching before she got her claws on a hefty jagged rock. With Alphys gone, it meant she had the time to work on her project. 

Operation: 'Fuck off, Jerry,' was working so far. Undyne wasn't oblivious to the man complaining to anyone in earshot about how smelly his house was. Bemoaning his bad luck.

Okay maybe she needed to finalize a name one day, but the point still stood! Jerry needed to be gone. With what results she had so far, Undyne knew she needed to keep going.

She grunted, releasing a stream of bubbles as she used all her strength to lift the rock up and hold it close. The swim back to shore was a slow one, one that left Undyne more tired than she had been in years. She sure wasn't exactly a guppy anymore after all.

She poked her head out of the water squinting out at the beach. Undyne dropped the rock for now, swimming closer to the beach to properly investigate. If she was going to execute this plan, she was going to do it right.

Jerry's car was still parked by the shore. _Good_. The jerk had left it parked in his backyard overnight. 

The mermaid ducked back underwater, moving to grab the rock and hefting it up with all her strength. She swam closer to the beach's edge, pushing herself up and lifting the rock up. 

The sound of a car alarm blared loudly through the night as a mermaid swam home laughing. Playing by human rules was for _wimps_. 

\----

"H-Huh." Alphys sorted through the mail, pausing at a folded over piece of notebook paper. She unfolded it curiously blinking in surprise at the wild scribbling within. This wasn't a normal letter by any stretch of the imagination. 

"Whatcha lookin' at babe?" Undyne called out from the wet couch, stretching out lazily as Alphys walked back towards their living room area. "W-w-well, someone broke Jerry's car window apparently?" She showed her girlfriend the note, a puzzled expression on her face. She turned the page around to re-read it. 

"He's threatening to sue the whole neighborhood if someone doesn't apologize." 

"Isn't that like... impossible?" 

"Y-Yeah." Alphys answered with a laugh. "The letter kind of is weird. He starts rambling about someone putting trash in his yard too? I know you did that at least for awhile. But the weird smell I don't get."

"Weird smell?" Undyne for her part could play innocent. 

"Mhmm. He spends like three paragraphs talking about someone putting stink bombs in his house." Alphys simply shook her head, bemused at the whole thing. She paused to squint at her wife. "Y-You didn't put stink bombs in his house did you?" 

"Nah. Where would I even get 'em?" Undyne questioned with a lazy stretch. Immensely glad she couldn't sweat. She could play it cool. The coolest. "Sides how would I even get to his house?" 

"T-True." Any suspicion on Alphy's part faded. "You're kinda waterlogged most of the time." She spared their damp couch a glance for emphasis. Undyne flashed her an innocent smile full of jagged teeth.

\-----

The letters only escalated from there. Almost weekly Jerry had another passive aggressive letter put in people's mailboxes and pinned to light posts nearby houses. 

He was offering 10 dollars to the first person to find the culprit for his troubles. Unsurprisingly no one really cared, which only made the letters and notices more numerous. Going from weekly to nearly daily output from the rich twenty something who inherited beach side property from a distant relative who didn't know him very well. He switched from handwritten to printed notices after a certain point, which only made his out put more of a problem.

"O-Oh my god." Alphys dumped out five letters from Jerry alone onto the kitchen table. "This is getting weird." 

"Getting weird? Hasn't this guy always been weird?" Undyne hadn't even pushed her project any farther, with Alphys home she was more content to sit around with her human wife watching anime.

"Y-Yeah. Neighborhood parties get kind of uncomfortable with Jerry around." Everyone ditched him as soon as possible. Even his family members seemed to gravitate away from him. He was an unpleasant person with a penchant about complaining about how everyone but himself was boring or somehow terrible. 

"Last time I think the whole block ditched to get pizza. I-I kinda cut out early." Alphys was never a party person, much less with her snootier neighbors. "He was complaining about it for ages though." 

"You think he'd be used to it." Undyne shifted through the letters, able to guess which was most recent by how big the type size was. The mermaid squinted at the letter, bringing it closer to her face. "I think he misspelled his name here..." 

\-----

"Well, good news I guess." Alphys announced as she stepped into the house, letters in hand. She closed the front door with her hip, walking inside to greet her wife at the pool. "Jerry is officially moving away." 

Undyne blinked at that, "Seriously?" 

"Y-Yep." She leaned down to kiss Undyne on the cheek before dropping the letters on the low table next to the couch. "He m-made a big announcement at the block association meeting today. It was p-pretty awkward." 

Undyne grimaced. "Yeeowch." What she knew from Alphys vague descriptions of block association meetings, it wasn't exactly the greatest thing.

"Someone applauded and there was a- uh incident." 

Undyne arched her brows imploring her wife to continue. Her the fins on her face flipped forward slightly with Undyne's curiosity. "Incident?" 

"Jerry tried to pick a fight with Arron." Alphys awkward wrinkled her nose, she was still having a hard time dealing with the fact she watched Arron suplex someone through a fold up table. "They broke a table in the process. T-The police showed up." 

Undyne grimaced openly again at her wife's words. One hand it was kind of hilarious, on the other she hadn't expected that. "Wow."

"I think his n-nose was broken. Not sure. I kinda stayed out of the way." She shook her head, nervously laughing. "I-I can't believe that happened." "Guess it was one of the better meetings then?" The mermaid joked with a toothy grin.

\----

Predictably three weeks later, the house was up for sale while Jerry nursed a broken nose and even worse attitude than ever before. A few letters of court mandated apologies were sent to any parties offended by the fight. 

Alphys joked that it was the second most sarcastic apology letter she had ever gotten.

Undyne helpfully got rid of the 'strange smell' lingering under the house the day she knew her wife was going to go take a peek at it. Mission 'Get Rid of Jerry' was an accomplishment, no more need for her stash. The seagulls could take care of it for her. Alphys didn't hesitate to buy the house after taking a look around. She really had to wonder just what Jerry was talking about. The house didn't smell too bad, maybe like old fish and dirty laundry. With some airing out and modified landscaping it to spruce it up, it would be perfect. 

Undyne simply cackled to herself whilst playing piano loudly in victory. The water proof cellphone sat nearby, Alphys's texts still open. _*I don't know what Jerry's talking about. *The house seems fine! *I bought it_

\-----

She lazily tucked her head under Alphy’s chin, rumbling lowly at the warmth radiating from her spouse. The sunlight trickling in from the window over their bed and natural body heat Alphys produced left the mermaid comfortable. Everything was right in the world. 

“G-Geeze.” Alphys laughed, brushing her fingers across the fins on the side of her partner’s face. “You’re in a great mood.” 

“You always put me in a great mood.” She opened her good eye partially, squinting up at the human woman. “Just keep being a babe and it’ll continue.” 

Alphys sputtered a little, turning red in the process. “F-Flatterer.” Undyne just grinned, moving to roll onto her wife properly, planting several kisses across the human’s face. Alphys just squeaked a little in surprise at first before returning the attention. Even with the shift of scales and skin, the two found themselves in familiar territory. Years of marriage and companionship meant they knew each other’s bodies far too well. Alphys navigated past the threat of a fang amidst the kiss, deepening it and gently tangling her fingers in Undyne’s still wet hair. 

The mermaid groaned into the kiss, her eye closing as she felt familiar fingers brush across her gills. She let her hand drop to brush across the human’s side, drifting up and under her shirt to cup Alphys breast. The sixty year old human squirmed at the attention, breath catching in the back of her throat. Undyne flicked her scaled fingertip across Alphys nipple teasingly, resisting her urge to fully undress her wife. 

“I’m speaking the truth. Grade A Babe.” Undyne laughed when she broke away from the kiss. She licked her lips, tasting her wife on her lips. That cherry pineapple lipgloss was as familiar as the contented flush on Alphys cheeks. 

“I’d love to keep doing this, but- we gotta get up right?” She questioned with a tilt of her head. Alphys jerked up nearly sending her wife falling off the bed. “Oh my god! U-Undyne, Sorry!” 

“No big deal.” Undyne grunted in turn with a wave of her hand. She reluctantly shifted off off Alphys to drop into the waterway next to the bed. She emerged with a toss of her hair, continuing the conversation. “I wouldn’t mind getting more close and personal but I think everyone is coming for dinner right?” 

“Y-Yeah!” She sputtered, tugging her shirt down and smoothing her hands across her skirt. “Thank god we’re ordering food. I don’t think cooking would be the best idea.” 

“Hope they like Japanese food.” No one really complained after the spaghetti incident of 2017. Papyrus and Undyne were banned from trying to cook anything that wasn’t microwaveable. 

“I-I’m sure they will.” Alphys reluctantly stepped towards the closet finding a shirt and tucking it in one of her pockets. “I know Frisk likes it a lot.”

“Sans also doesn’t really care either way.” Undyne answered with a snort, “Long as we’re feeding him, he’ll eat it. Probably pour ketchup on it too.” 

All Alphys could do was groan at the thought, covering her face with her hands. “Don’t remind me!” With that she strode out of their bedroom. Undyne lingered to watch her wife walk away before diving back into the waterway. 

Navigating through the waterway was old hat by now. Each room was connected in some way to the flowing waterway Alphys had built into the house. Even now Undyne marveled at the complex glass and metal tubes that let her travel through the house without being carried. Their first few years together and the wheel barrow had left a mark or two neither wanted to relive. She swam easily through the tube, ignoring the occasional lost fish that sped by in favor of finding her way to the main room. 

She emerged with a splash, cutting through the water with practice. Alphys was already there, seated at the piano’s bench. The mermaid reeled back and tossed herself forward onto the bench readily. Only minor splashing hit the concrete around the piano and Alphy’s shoes. The scientist spared her shoes a glance, but didn’t seem to mind. She pulled the shirt she pilfered from the closet out of her pocket, presenting it to the mermaid. 

“I know you aren’t fond of shirts b-but you know how Toriel is.” 

“Eh. I know her, big punk doesn’t know what she’s missing.” She shrugged a little accepting the shirt to examine it. The fact it wasn’t a Mew Mew: Kissy Cutie shirt said a lot about the dinner. “So this is a serious night, huh?” It was a lot more covering than Undyne was used to. Something humans wore when they wanted to look nice. If this was a nice night for mermaids she’d be wearing bones and cool glittery rocks. One of these days Undyne was going to convince one of these humans her skull headdress was in fact perfectly suitable for day to day wear. She would compromise and wear one of those crop tops Papyrus found for her. 

“W-well, I did kind of buy a house for them.” 

Undyne passed the shirt back with a snort, “Hold onto it for now. We’re eating by the pool, ya goof. I’ll just get it wet when I have to go over there.” 

“O-Oh! Right!” She nervously fumbled with the shirt before hugging it to her chest. The scientist leaned back, nervous energy clear on her face. “I-I’m such a wreck. What if I’m imposing? What if Toriel hates it? What if-“ 

Undyne simply reached over to yank the shirt out of Alphy’s hands dropping it on the piano before yanking the plump nerd into a very fierce and wet embrace. “None of that ‘what if’ crap! They’re your clan, your pod- family. You’re doing good, you dork. They want this as much as you do! No what ifs or buts about it, you hear?!” 

Alphys just pressed her face against Undyne’s shoulder, hugging her tightly back. “I-I hear you.” Undyne knew that didn’t magically fix all her anxieties, but it helped. It was the best they could do for each other. Alphys pulled away after a moment, smiling at the mermaid. 

“You’re so cute.” 

“Whaaa- no way!” 

“A-Adorable.” 

“I’m fearsome! I eat sharks for breakfast!” Undyne's tail slapped the concrete with an audible thud. 

“You ate cereal with me this morning.” Alphys laughed in turn, covering her mouth as she did so. One day Undyne was going to figure a way to see that laugh without Alphys trying to cover her mouth. Whoever told Alphys her teeth were ‘weird’ would pay. 

“….There were shark shaped marshmallows. It doesn’t invalidate my argument.” 

“Mhmm.” Alphys just smiled softly back, her nerves starting to ease. Undyne could see as much in the human’s face. “You know I love you, right?”

“I do.” Undyne brushed her fingers against Alphys cheek. "I love you too." 

The quiet of the moment didn't last long as the doorbell rang. Rang repeatedly. Papyrus was manning the buzzer. Alphys reluctantly pulled away from Undyne, standing up from the bench. "C-Coming!" 

Undyne didn't need much encouragement to launch herself off of the bench into the pool, emerging with a splash and shake of her hair. She smiled as Alphys skittered across the bridge between the piano island in the pool to the main part of the living area. She gently left the shirt by Undyne before heading off towards the entry way. 

After some drying off, Undyne slipped the shirt on, yanking herself upwards onto the concrete poolside. With some shifting she found a comfortable enough position to keep her tail in the water while the rest of her was out of it. She yanked the shirt up and over her head, brushing out any wrinkles. Undyne wasn't alone long as Frisk camp scampering in, Papyrus on their tail the two happily greeting their favorite mermaid.


End file.
